The present invention relates to an improved archery bow handle riser and a method for producing the same, and more particularly relates to an improvement in safety of an archery bow handle riser including a FRP shell and its production.
In general, the handle riser of an archery bow is made of materials such as FRP (fiber reinforced plastics) and light metals. Regardless of the materials used for production, the archery bow is apt to break near the pivot point on the grip at the end of its life caused by fatigue and/or corrosion of the material. When such breakage occurs, the broken half of the archery bow, in particular the one not gripped by the archer's hand, tends to jump towards the archer with a risk of hurting the archer.
In order to avoid such a risk, it is best to estimate the end of life of an archery bow handle riser. In practice, however, it is quite infeasible to correctly estimate the end of life of an archery bow handle riser which is greatly swayed by various factors such as manner of use by the archer, inherent strength of the archery bow, choice of strings and arrows, frequency of use, manner and condition of storage, degree of maintenance and climatic conditions. That is, there is no established standard for estimation of life.
It is already proposed with an archery bow including a cast handle riser made of Mg alloys to connect sections on both sides of the grip with a hand or the like for archer's safety at breakage. When the handle riser breaks at shooting, however, elastic recovery of the limb rotates the broken half which is liable to jump towards the archer. So, no reliable safety is assured by this earlier proposal.
An archery bow handle riser having a cavitious FRP shell is also known but, in the case of this type, no safety at breakage is taken into consideration.